CITY ROOM; For New Floor Tiles, Grand Central Turns to an Old Quarry

By MICHAEL M. GRYNBAUM

Published: June 15, 2010

You can gaze at its constellation-filled ceiling, or admire those sky-high Corinthian columns, but there is one way to appreciate the neo-Classical splendor of Grand Central Terminal that does not require a craned neck: stare at the floor.

At your feet, you will find acres of smooth pink marble, a luxurious surface more often found in the lobby of grand banking institutions than public transportation hubs.

The floor tiles are made of the same storied stuff - Tennessee pink marble - that is used in the beloved buildings of McKim, Mead & White, including landmarks like J. P. Morgan's library and the James A. Farley Post Office (not to mention the original Pennsylvania Station).

So when it came time to restore the floor, parts of which had cracked, officials at the Metro-North Railroad called up the quarry in the Volunteer State that produced the original stone for the terminal, which opened in 1913. The quarry closed in the 1980s, but the owners agreed to reopen so Grand Central could match its new tiles with the original marble hue.

About 45,000 square feet of marble tile will be replaced in the five-year program, which is scheduled to end in 2012, according to the railroad's newsletter, Mileposts. Another 65,000 square feet of tiles will be produced using custom terrazzo, described by Mileposts as ''consisting of marble chips set in cement or epoxy resin that is poured and ground smooth when dry.''

Like the Coca-Cola formula, the exact type of terrazzo used in the terminal remains a secret. Officials at the railroad experimented with several mixtures to match colors with the original material.

When the terminal opened, the marble tiles were separated by one-sixteenth of an inch, a tight squeeze that contributed to cracks. The new slabs have double that space, although officials insist that the human eye cannot tell the difference.

Ack!-ronym

Among the better-known abbreviations of the Internet - LOL for ''laugh out loud,'' OMG for ''oh, my God'' - is one that stems from coarser origins. It refers to a particular self-denigrating put-down, something one might moan when confronted with a dispiriting turn in one's life.

The Metropolitan Transportation Authority, however, has deemed the letters' construction suitable for consumption by the mass transit riding public. Thanks to a juggling of subway lines, part of the service cuts set to begin later this month, the M train will replace the V train in several stations along Avenue of the Americas in Manhattan.

At the 14th Street station, the F and M trains will intersect with the crosstown L line. As part of its preparation for the service cuts, transit officials updated the station's signs over the weekend. As a result, a station previously labeled ''F/V/L'' now advertises itself ''F/M/L.''

Our transit reporter, Michael M. Grynbaum, advises you on the latest chatter from the city's roads and rails. Check back first thing every Monday morning. Got a tip? He can be reached at OffTheRails@nytimes.com.

This is a more complete version of the story than the one that appeared in print.

PHOTO: A shuttered Tennessee quarry that supplied the original stone for Grand Central Terminal has reopened to aid with floor repairs. (PHOTOGRAPH BY RICHARD PERRY/THE NEW YORK TIMES)